LCOV - code coverage report
Current view: directory - js/src - jsatom.h (source / functions) Found Hit Coverage
Test: app.info Lines: 59 57 96.6 %
Date: 2012-04-07 Functions: 23 23 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2                 :  *
       3                 :  * ***** BEGIN LICENSE BLOCK *****
       4                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       5                 :  *
       6                 :  * The contents of this file are subject to the Mozilla Public License Version
       7                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       8                 :  * the License. You may obtain a copy of the License at
       9                 :  * http://www.mozilla.org/MPL/
      10                 :  *
      11                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      12                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      13                 :  * for the specific language governing rights and limitations under the
      14                 :  * License.
      15                 :  *
      16                 :  * The Original Code is Mozilla Communicator client code, released
      17                 :  * March 31, 1998.
      18                 :  *
      19                 :  * The Initial Developer of the Original Code is
      20                 :  * Netscape Communications Corporation.
      21                 :  * Portions created by the Initial Developer are Copyright (C) 1998
      22                 :  * the Initial Developer. All Rights Reserved.
      23                 :  *
      24                 :  * Contributor(s):
      25                 :  *
      26                 :  * Alternatively, the contents of this file may be used under the terms of
      27                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      28                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      29                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      30                 :  * of those above. If you wish to allow use of your version of this file only
      31                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      32                 :  * use your version of this file under the terms of the MPL, indicate your
      33                 :  * decision by deleting the provisions above and replace them with the notice
      34                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      35                 :  * the provisions above, a recipient may use your version of this file under
      36                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      37                 :  *
      38                 :  * ***** END LICENSE BLOCK ***** */
      39                 : 
      40                 : #ifndef jsatom_h___
      41                 : #define jsatom_h___
      42                 : 
      43                 : #include <stddef.h>
      44                 : #include "jsversion.h"
      45                 : #include "jsalloc.h"
      46                 : #include "jsapi.h"
      47                 : #include "jsprvtd.h"
      48                 : #include "jshash.h"
      49                 : #include "jspubtd.h"
      50                 : #include "jslock.h"
      51                 : 
      52                 : #include "gc/Barrier.h"
      53                 : #include "js/HashTable.h"
      54                 : 
      55                 : struct JSIdArray {
      56                 :     int length;
      57                 :     js::HeapId vector[1];    /* actually, length jsid words */
      58                 : };
      59                 : 
      60                 : /* Engine-internal extensions of jsid */
      61                 : 
      62                 : static JS_ALWAYS_INLINE jsid
      63        99353608 : JSID_FROM_BITS(size_t bits)
      64                 : {
      65                 :     jsid id;
      66        99353608 :     JSID_BITS(id) = bits;
      67                 :     return id;
      68                 : }
      69                 : 
      70                 : static JS_ALWAYS_INLINE jsid
      71        99353608 : ATOM_TO_JSID(JSAtom *atom)
      72                 : {
      73        99353608 :     JS_ASSERT(((size_t)atom & 0x7) == 0);
      74        99353608 :     return JSID_FROM_BITS((size_t)atom);
      75                 : }
      76                 : 
      77                 : /* All strings stored in jsids are atomized. */
      78                 : static JS_ALWAYS_INLINE JSBool
      79       174392100 : JSID_IS_ATOM(jsid id)
      80                 : {
      81       174392100 :     return JSID_IS_STRING(id);
      82                 : }
      83                 : 
      84                 : static JS_ALWAYS_INLINE JSBool
      85        22506104 : JSID_IS_ATOM(jsid id, JSAtom *atom)
      86                 : {
      87        22506104 :     return JSID_BITS(id) == JSID_BITS(ATOM_TO_JSID(atom));
      88                 : }
      89                 : 
      90                 : static JS_ALWAYS_INLINE JSAtom *
      91       200620575 : JSID_TO_ATOM(jsid id)
      92                 : {
      93       200620575 :     return (JSAtom *)JSID_TO_STRING(id);
      94                 : }
      95                 : 
      96                 : extern jsid
      97                 : js_CheckForStringIndex(jsid id);
      98                 : 
      99                 : JS_STATIC_ASSERT(sizeof(JSHashNumber) == 4);
     100                 : JS_STATIC_ASSERT(sizeof(jsid) == JS_BYTES_PER_WORD);
     101                 : 
     102                 : namespace js {
     103                 : 
     104                 : static JS_ALWAYS_INLINE JSHashNumber
     105        55247233 : HashId(jsid id)
     106                 : {
     107        55247233 :     JS_ASSERT(js_CheckForStringIndex(id) == id);
     108                 :     JSHashNumber n =
     109                 : #if JS_BYTES_PER_WORD == 4
     110        55247233 :         JSHashNumber(JSID_BITS(id));
     111                 : #elif JS_BYTES_PER_WORD == 8
     112                 :         JSHashNumber(JSID_BITS(id)) ^ JSHashNumber(JSID_BITS(id) >> 32);
     113                 : #else
     114                 : # error "Unsupported configuration"
     115                 : #endif
     116        55247233 :     return n * JS_GOLDEN_RATIO;
     117                 : }
     118                 : 
     119                 : static JS_ALWAYS_INLINE Value
     120         3000001 : IdToValue(jsid id)
     121                 : {
     122         3000001 :     if (JSID_IS_STRING(id))
     123         2977195 :         return StringValue(JSID_TO_STRING(id));
     124           22806 :     if (JS_LIKELY(JSID_IS_INT(id)))
     125           22752 :         return Int32Value(JSID_TO_INT(id));
     126              54 :     if (JS_LIKELY(JSID_IS_OBJECT(id)))
     127              54 :         return ObjectValue(*JSID_TO_OBJECT(id));
     128               0 :     JS_ASSERT(JSID_IS_DEFAULT_XML_NAMESPACE(id) || JSID_IS_VOID(id));
     129               0 :     return UndefinedValue();
     130                 : }
     131                 : 
     132                 : static JS_ALWAYS_INLINE jsval
     133           11668 : IdToJsval(jsid id)
     134                 : {
     135           11668 :     return IdToValue(id);
     136                 : }
     137                 : 
     138                 : template<>
     139                 : struct DefaultHasher<jsid>
     140                 : {
     141                 :     typedef jsid Lookup;
     142              63 :     static HashNumber hash(const Lookup &l) {
     143              63 :         JS_ASSERT(l == js_CheckForStringIndex(l));
     144              63 :         return HashNumber(JSID_BITS(l));
     145                 :     }
     146               9 :     static bool match(const jsid &id, const Lookup &l) {
     147               9 :         JS_ASSERT(l == js_CheckForStringIndex(l));
     148               9 :         return id == l;
     149                 :     }
     150                 : };
     151                 : 
     152                 : }
     153                 : 
     154                 : #if JS_BYTES_PER_WORD == 4
     155                 : # define ATOM_HASH(atom)          ((JSHashNumber)(atom) >> 2)
     156                 : #elif JS_BYTES_PER_WORD == 8
     157                 : # define ATOM_HASH(atom)          (((JSHashNumber)(uintptr_t)(atom) >> 3) ^   \
     158                 :                                    (JSHashNumber)((uintptr_t)(atom) >> 32))
     159                 : #else
     160                 : # error "Unsupported configuration"
     161                 : #endif
     162                 : 
     163                 : /*
     164                 :  * Return a printable, lossless char[] representation of a string-type atom.
     165                 :  * The lifetime of the result matches the lifetime of bytes.
     166                 :  */
     167                 : extern const char *
     168                 : js_AtomToPrintableString(JSContext *cx, JSAtom *atom, JSAutoByteString *bytes);
     169                 : 
     170                 : namespace js {
     171                 : 
     172                 : /* Compute a hash function from chars/length. */
     173                 : inline uint32_t
     174        31974399 : HashChars(const jschar *chars, size_t length)
     175                 : {
     176        31974399 :     uint32_t h = 0;
     177       429252977 :     for (; length; chars++, length--)
     178       397278578 :         h = JS_ROTATE_LEFT32(h, 4) ^ *chars;
     179        31974399 :     return h;
     180                 : }
     181                 : 
     182                 : class AtomStateEntry
     183                 : {
     184                 :     uintptr_t bits;
     185                 : 
     186                 :     static const uintptr_t NO_TAG_MASK = uintptr_t(-1) - 1;
     187                 : 
     188                 :   public:
     189        70161698 :     AtomStateEntry() : bits(0) {}
     190        42316465 :     AtomStateEntry(const AtomStateEntry &other) : bits(other.bits) {}
     191        11865225 :     AtomStateEntry(JSAtom *ptr, bool tagged)
     192        11865225 :       : bits(uintptr_t(ptr) | uintptr_t(tagged))
     193                 :     {
     194        11865225 :         JS_ASSERT((uintptr_t(ptr) & 0x1) == 0);
     195        11865225 :     }
     196                 : 
     197        42316478 :     bool isTagged() const {
     198        42316478 :         return bits & 0x1;
     199                 :     }
     200                 : 
     201                 :     /*
     202                 :      * Non-branching code sequence. Note that the const_cast is safe because
     203                 :      * the hash function doesn't consider the tag to be a portion of the key.
     204                 :      */
     205        20105255 :     void setTagged(bool enabled) const {
     206        20105255 :         const_cast<AtomStateEntry *>(this)->bits |= uintptr_t(enabled);
     207        20105255 :     }
     208                 : 
     209                 :     JSAtom *asPtr() const;
     210                 : };
     211                 : 
     212                 : struct AtomHasher
     213                 : {
     214                 :     struct Lookup
     215                 :     {
     216                 :         const jschar    *chars;
     217                 :         size_t          length;
     218                 :         const JSAtom    *atom; /* Optional. */
     219                 : 
     220        43835704 :         Lookup(const jschar *chars, size_t length) : chars(chars), length(length), atom(NULL) {}
     221                 :         inline Lookup(const JSAtom *atom);
     222                 :     };
     223                 : 
     224        31970493 :     static HashNumber hash(const Lookup &l) { return HashChars(l.chars, l.length); }
     225                 :     static inline bool match(const AtomStateEntry &entry, const Lookup &lookup);
     226                 : };
     227                 : 
     228                 : typedef HashSet<AtomStateEntry, AtomHasher, SystemAllocPolicy> AtomSet;
     229                 : 
     230                 : /*
     231                 :  * On encodings:
     232                 :  *
     233                 :  * - Some string functions have an optional FlationCoding argument that allow
     234                 :  *   the caller to force CESU-8 encoding handling. 
     235                 :  * - Functions that don't take a FlationCoding base their NormalEncoding
     236                 :  *   behavior on the js_CStringsAreUTF8 value. NormalEncoding is either raw
     237                 :  *   (simple zero-extension) or UTF-8 depending on js_CStringsAreUTF8.
     238                 :  * - Functions that explicitly state their encoding do not use the
     239                 :  *   js_CStringsAreUTF8 value.
     240                 :  *
     241                 :  * CESU-8 (Compatibility Encoding Scheme for UTF-16: 8-bit) is a variant of
     242                 :  * UTF-8 that allows us to store any wide character string as a narrow
     243                 :  * character string. For strings containing mostly ascii, it saves space.
     244                 :  * http://www.unicode.org/reports/tr26/
     245                 :  */
     246                 : 
     247                 : enum FlationCoding
     248                 : {
     249                 :     NormalEncoding,
     250                 :     CESU8Encoding
     251                 : };
     252                 : 
     253                 : class PropertyName;
     254                 : 
     255                 : }  /* namespace js */
     256                 : 
     257                 : struct JSAtomState
     258           37522 : {
     259                 :     js::AtomSet         atoms;
     260                 : 
     261                 :     /*
     262                 :      * From this point until the end of struct definition the struct must
     263                 :      * contain only js::PropertyName fields. We use this to access the storage
     264                 :      * occupied by the common atoms in js_FinishCommonAtoms.
     265                 :      *
     266                 :      * js_common_atom_names defined in jsatom.cpp contains C strings for atoms
     267                 :      * in the order of atom fields here. Therefore you must update that array
     268                 :      * if you change member order here.
     269                 :      */
     270                 : 
     271                 :     /* The rt->emptyString atom, see jsstr.c's js_InitRuntimeStringState. */
     272                 :     js::PropertyName    *emptyAtom;
     273                 : 
     274                 :     /*
     275                 :      * Literal value and type names.
     276                 :      * NB: booleanAtoms must come right before typeAtoms!
     277                 :      */
     278                 :     js::PropertyName    *booleanAtoms[2];
     279                 :     js::PropertyName    *typeAtoms[JSTYPE_LIMIT];
     280                 :     js::PropertyName    *nullAtom;
     281                 : 
     282                 :     /* Standard class constructor or prototype names. */
     283                 :     js::PropertyName    *classAtoms[JSProto_LIMIT];
     284                 : 
     285                 :     /* Various built-in or commonly-used atoms, pinned on first context. */
     286                 : #define DEFINE_ATOM(id, text)          js::PropertyName *id##Atom;
     287                 : #define DEFINE_PROTOTYPE_ATOM(id)      js::PropertyName *id##Atom;
     288                 : #define DEFINE_KEYWORD_ATOM(id)        js::PropertyName *id##Atom;
     289                 : #include "jsatom.tbl"
     290                 : #undef DEFINE_ATOM
     291                 : #undef DEFINE_PROTOTYPE_ATOM
     292                 : #undef DEFINE_KEYWORD_ATOM
     293                 : 
     294                 :     /* Less frequently used atoms, pinned lazily by JS_ResolveStandardClass. */
     295                 :     struct {
     296                 :         js::PropertyName *XMLListAtom;
     297                 :         js::PropertyName *decodeURIAtom;
     298                 :         js::PropertyName *decodeURIComponentAtom;
     299                 :         js::PropertyName *defineGetterAtom;
     300                 :         js::PropertyName *defineSetterAtom;
     301                 :         js::PropertyName *encodeURIAtom;
     302                 :         js::PropertyName *encodeURIComponentAtom;
     303                 :         js::PropertyName *escapeAtom;
     304                 :         js::PropertyName *hasOwnPropertyAtom;
     305                 :         js::PropertyName *isFiniteAtom;
     306                 :         js::PropertyName *isNaNAtom;
     307                 :         js::PropertyName *isPrototypeOfAtom;
     308                 :         js::PropertyName *isXMLNameAtom;
     309                 :         js::PropertyName *lookupGetterAtom;
     310                 :         js::PropertyName *lookupSetterAtom;
     311                 :         js::PropertyName *parseFloatAtom;
     312                 :         js::PropertyName *parseIntAtom;
     313                 :         js::PropertyName *propertyIsEnumerableAtom;
     314                 :         js::PropertyName *unescapeAtom;
     315                 :         js::PropertyName *unevalAtom;
     316                 :         js::PropertyName *unwatchAtom;
     317                 :         js::PropertyName *watchAtom;
     318                 :     } lazy;
     319                 : 
     320                 :     static const size_t commonAtomsOffset;
     321                 :     static const size_t lazyAtomsOffset;
     322                 : 
     323           18761 :     void clearLazyAtoms() {
     324           18761 :         memset(&lazy, 0, sizeof(lazy));
     325           18761 :     }
     326                 : 
     327           18761 :     void junkAtoms() {
     328                 : #ifdef DEBUG
     329           18761 :         memset(commonAtomsStart(), JS_FREE_PATTERN, sizeof(*this) - commonAtomsOffset);
     330                 : #endif
     331           18761 :     }
     332                 : 
     333           37522 :     JSAtom **commonAtomsStart() {
     334           37522 :         return reinterpret_cast<JSAtom **>(&emptyAtom);
     335                 :     }
     336                 : 
     337                 :     void checkStaticInvariants();
     338                 : };
     339                 : 
     340                 : extern bool
     341                 : AtomIsInterned(JSContext *cx, JSAtom *atom);
     342                 : 
     343                 : #define ATOM(name) cx->runtime->atomState.name##Atom
     344                 : 
     345                 : #define COMMON_ATOM_INDEX(name)                                               \
     346                 :     ((offsetof(JSAtomState, name##Atom) - JSAtomState::commonAtomsOffset)     \
     347                 :      / sizeof(JSAtom*))
     348                 : #define COMMON_TYPE_ATOM_INDEX(type)                                          \
     349                 :     ((offsetof(JSAtomState, typeAtoms[type]) - JSAtomState::commonAtomsOffset)\
     350                 :      / sizeof(JSAtom*))
     351                 : 
     352                 : #define ATOM_OFFSET(name)       offsetof(JSAtomState, name##Atom)
     353                 : #define OFFSET_TO_ATOM(rt,off)  (*(JSAtom **)((char*)&(rt)->atomState + (off)))
     354                 : #define CLASS_ATOM_OFFSET(name) offsetof(JSAtomState, classAtoms[JSProto_##name])
     355                 : #define CLASS_ATOM(cx,name)     ((cx)->runtime->atomState.classAtoms[JSProto_##name])
     356                 : 
     357                 : extern const char *const js_common_atom_names[];
     358                 : extern const size_t      js_common_atom_count;
     359                 : 
     360                 : /*
     361                 :  * Macros to access C strings for JSType and boolean literals.
     362                 :  */
     363                 : #define JS_BOOLEAN_STR(type) (js_common_atom_names[1 + (type)])
     364                 : #define JS_TYPE_STR(type)    (js_common_atom_names[1 + 2 + (type)])
     365                 : 
     366                 : /* Type names. */
     367                 : extern const char   js_object_str[];
     368                 : extern const char   js_undefined_str[];
     369                 : 
     370                 : /* Well-known predefined C strings. */
     371                 : #define JS_PROTO(name,code,init) extern const char js_##name##_str[];
     372                 : #include "jsproto.tbl"
     373                 : #undef JS_PROTO
     374                 : 
     375                 : #define DEFINE_ATOM(id, text)  extern const char js_##id##_str[];
     376                 : #define DEFINE_PROTOTYPE_ATOM(id)
     377                 : #define DEFINE_KEYWORD_ATOM(id)
     378                 : #include "jsatom.tbl"
     379                 : #undef DEFINE_ATOM
     380                 : #undef DEFINE_PROTOTYPE_ATOM
     381                 : #undef DEFINE_KEYWORD_ATOM
     382                 : 
     383                 : #if JS_HAS_GENERATORS
     384                 : extern const char   js_close_str[];
     385                 : extern const char   js_send_str[];
     386                 : #endif
     387                 : 
     388                 : /* Constant strings that are not atomized. */
     389                 : extern const char   js_getter_str[];
     390                 : extern const char   js_setter_str[];
     391                 : 
     392                 : /*
     393                 :  * Initialize atom state. Return true on success, false on failure to allocate
     394                 :  * memory. The caller must zero rt->atomState before calling this function and
     395                 :  * only call it after js_InitGC successfully returns.
     396                 :  */
     397                 : extern JSBool
     398                 : js_InitAtomState(JSRuntime *rt);
     399                 : 
     400                 : /*
     401                 :  * Free and clear atom state including any interned string atoms. This
     402                 :  * function must be called before js_FinishGC.
     403                 :  */
     404                 : extern void
     405                 : js_FinishAtomState(JSRuntime *rt);
     406                 : 
     407                 : /*
     408                 :  * Atom tracing and garbage collection hooks.
     409                 :  */
     410                 : 
     411                 : namespace js {
     412                 : 
     413                 : extern void
     414                 : MarkAtomState(JSTracer *trc, bool markAll);
     415                 : 
     416                 : extern void
     417                 : SweepAtomState(JSRuntime *rt);
     418                 : 
     419                 : extern bool
     420                 : InitCommonAtoms(JSContext *cx);
     421                 : 
     422                 : extern void
     423                 : FinishCommonAtoms(JSRuntime *rt);
     424                 : 
     425                 : /* N.B. must correspond to boolean tagging behavior. */
     426                 : enum InternBehavior
     427                 : {
     428                 :     DoNotInternAtom = false,
     429                 :     InternAtom = true
     430                 : };
     431                 : 
     432                 : }  /* namespace js */
     433                 : 
     434                 : extern JSAtom *
     435                 : js_Atomize(JSContext *cx, const char *bytes, size_t length,
     436                 :            js::InternBehavior ib = js::DoNotInternAtom,
     437                 :            js::FlationCoding fc = js::NormalEncoding);
     438                 : 
     439                 : extern JSAtom *
     440                 : js_AtomizeChars(JSContext *cx, const jschar *chars, size_t length,
     441                 :                 js::InternBehavior ib = js::DoNotInternAtom);
     442                 : 
     443                 : extern JSAtom *
     444                 : js_AtomizeString(JSContext *cx, JSString *str, js::InternBehavior ib = js::DoNotInternAtom);
     445                 : 
     446                 : /*
     447                 :  * Return an existing atom for the given char array or null if the char
     448                 :  * sequence is currently not atomized.
     449                 :  */
     450                 : extern JSAtom *
     451                 : js_GetExistingStringAtom(JSContext *cx, const jschar *chars, size_t length);
     452                 : 
     453                 : #ifdef DEBUG
     454                 : 
     455                 : extern JS_FRIEND_API(void)
     456                 : js_DumpAtoms(JSContext *cx, FILE *fp);
     457                 : 
     458                 : #endif
     459                 : 
     460                 : inline bool
     461                 : js_ValueToAtom(JSContext *cx, const js::Value &v, JSAtom **atomp);
     462                 : 
     463                 : inline bool
     464                 : js_ValueToStringId(JSContext *cx, const js::Value &v, jsid *idp);
     465                 : 
     466                 : inline bool
     467                 : js_InternNonIntElementId(JSContext *cx, JSObject *obj, const js::Value &idval,
     468                 :                          jsid *idp);
     469                 : inline bool
     470                 : js_InternNonIntElementId(JSContext *cx, JSObject *obj, const js::Value &idval,
     471                 :                          jsid *idp, js::Value *vp);
     472                 : 
     473                 : /*
     474                 :  * For all unmapped atoms recorded in al, add a mapping from the atom's index
     475                 :  * to its address. map->length must already be set to the number of atoms in
     476                 :  * the list and map->vector must point to pre-allocated memory.
     477                 :  */
     478                 : extern void
     479                 : js_InitAtomMap(JSContext *cx, js::AtomIndexMap *indices, JSAtom **atoms);
     480                 : 
     481                 : namespace js {
     482                 : 
     483                 : template<XDRMode mode>
     484                 : bool
     485                 : XDRAtom(XDRState<mode> *xdr, JSAtom **atomp);
     486                 : 
     487                 : } /* namespace js */
     488                 : 
     489                 : #endif /* jsatom_h___ */

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